Warp stop mechanism



May' 6, 1930. H. A. DAVIS WARPv STOP MECHANISM File d Aug. 2, 1928 Lfl/NVEg/TOR/ BX a ATTdkA/EY Patented May 6, 1930 UNITED STATES PATENTOFFICE.

HARRY A. DAVIS, HOPEDALE, MASSACHUSETTS, ASSIG'NOR TO DRAPERCORPORATION,

OF HOPEDALE, MASSACHUSETTS, CORPORATION OF MAINE V WARP sror MECHANISMApplication filed. August 2, 1928. Serial No. 297,006;

This invention relates to Warp stop mechanisms for looms or .warpers,and more particularly to the drop wires of such'mecha nisms which arenormally supported by the warp threads and serve to effect machinestoppage on the occurrence of a warp fault.

It is now the ordinary practice to provide drop wires of warp stopmotions with a passageway or hole through which a warp thread may bepassed to thereby support the drop wires upon the intact warp threadsand permit a drop wire to fall should the supporting warp thread breakor become too slack. The drop wires are usually constructed of lightmetal strips, each having a passageway for a warp thread formed by anopening through the metal strip from side to side, and since the warpthreads are under lengthwise tension, either in the loom or warper, thedrop wires are themselves twisted or turned about their verticallongitudinal axis at an angle to theline of travel of the warp threads.This angular position of the drop wires is objectionable because theyare arranged in banks or rows in close relation and the edges of thedrop wires chafe against the adjacent warp threads withinjurious effect7 and, whenreleased on the occurrence of a warp fault, the fallen dropwire may not properly cooperate with the detector mechanism.

One of the objects of the present inven-,

tion is to overcome those and other objections, and enable the dropwires to be supported upon the warpthreads with the sides of the side ofthe drop wire for the passage of the associated warp thread, with theresult that the warp thread does notpass from one side. to the other ofthe drop wire but remains only on one side thereof with no tendency totwist or turnthe drop wire angularly about its vertical axis, so thatthe sides of the drop wire remain parallel to the line of travel of thewarp threads, chafing of the warp threads against the edges of adjacentdrop wires is avoided, and the drop wire remains in proper relativeposition with the detector mechanism when released by the occurrence ofa warp fault.

The drop wires in the present instance of the invention are associatedwith warp stop mechanism of anyusual type, and each may be provided witha guide bar slot through which a guide may be passed to direct themovements of the drop wires, and, as a good practical form, the dropwires are shown as of the hair pin type having two legs, in one of'whichis formed the offset opening or passageway for the warp threads.

In this character of drop wire it is preferable to form one leg of thedrop wire wider than the other to accommodate the off-set opening orpassageway for the warp threads while the narrower leg may be positionedbetween adjacent warp threads and assist in maintaining the drop wiresin parallel relation with the line of travel of the warp.

The invention will best be made clear from the following description andthe accompanying drawings of one good practical form thereof.

In the drawings: i V

Fig. 1 is a. perspective view of parts of a warp stop mechanismand dropwires containing the present invention, some of the parts being shown insection;

2 is an edge view of one of the drop wlres;

Fig. 3 is a diagrammatic view in plan showing the drop wires and warpthreads on an enlarged scale in their associated relation.

Warp sto'p mechanisms may be generally classified as of two types, onein which a detector has an oscillating movement in the direction of theline of travel of the warp threads, and the other in which the detectoris given a reciprocating movement in a direction transversely of theloom.

In the illustrated'form of the invention as shown by the drawingsherewith, the warp stop mechanism is illustrated as of the second typeand only such p arts thereof are indicated as appear necessaryfor aproper understanding; of the present invention, which relates moreparticularly to the drop wires used in such mechanisms.

As shown by Fig. 1, the guide bar 1 is mounted on the loom frame, asusual, and extends transversely thereof, such guide bar in the presentinstance of the invention being provided with a series of teeth 2 anddepressions 3 between the teeth. The guide bar 1 is likewise provided,as shown, with a longitudinal groove orr-e'cess l in which is mountedthe movable detector bar 5 which also extends transversely of themachine and is provided with a series of teeth 6, the construction beingsuch that should a drop wire be released by its supporting warp threadit will drop and engage between the teeth of the bars and arrestmovement of the movable bar to thereby effect machine stoppage, and suchparts may all be of usual construction.

It is usual in warp stop mechanisms "to provide a warp rest on which thewarp threads nray be supported 'as they travel through the openings inthe drop wires, and one of such warp rests 7 is herein indicated, itbeing understood that any suitable number may be employed.

The drop wire 8 of the present invention is illustrated as of the hairpin type which lends itself advantageously for employment in a warp stopmechanism of'the general cha"- acter described. The drop wire 8 isprovided with a guide opening 9 which may extend the full length of thedrop wire or be otherwise formed, its purpose-being to provide anopening through which the guide bar 1 extends for the purpose of guidingthedrop wires in their movements.

At each side of the opening 9 of the drop wire is a leg portion,-one ofwhich, 10, is preferably somewhat wider than the other leg portion 11.The leg portion 10 is provided with an opening or passageway 12 throughwhich a warp thread a may be passed and by which the drop wire itselfmay be supported on the warp thread. The opening 12 in the drop wireisoif-set to one side thereof, as shown, the result being that when awarp thread ais passed through the opening or passageway thus ofi-settoone side of the drop wire, the warp thread itself does not pass fronione side to the opposite side of the drop wire but remains on one sidethereof, as indicated in Figs. 2 and S, and consequently exerts notwisting tendency to deflect the drop wire about its longitudinal axisinto an angular relation with the path of travel of the warp threads.

The off-set opening or passageway 12 may be variously formed, and in thepresent instance of the invention it is provided by punching or removinga portion of the drop wireand bending one of the walls at the front orback of the opening laterally of the side of the drop wire, as indicatedat 13, Fig. 2. Under the conditions stated, the deflected portion 13 ofthe drop wire affords a supporting seat 14 for the warp thread a when ithas passed through the opening at one side of the drop wire, and theopening 12 thus formed is closed at its lower portion, as indicated at15, thereby insuring that during the weaving operation any jumpingaction imparted to the drop wire by the warp threads in forming the shedwill not disengage the drop wire from its supporting warp thread.

lVhere the drop wire is of the hair pin type, as shown, the narrow leg11 of the drop wire takes position between the adjacent warp threads, asindicated in Fig. 1, but with no tendency to chafe the warp threads between which it extends, by reason of the fact that the drop wire itselfhas its side faces parallel to the line of travel of the warp threaih'i,and this disposition of the narrow leg of the drop wire further insuresthe C011- tinuing parallelism of the drop wire with the line of travelof the warp threads, so that in conjunction with the off-set opening orpassageway 12 the drop wire is maintained in proper relation tocooperate with the warp stop detector mechanism.

During the weaving operation the warp threads are under longitudinaltension and bear on only one side of the drop wires, as indicated at 16,where the warp thread passes through the oif-set opening 12, and also onthe same side of the leg portion 11, as indicated at 17, with the resultthat the tension of the war-p thread has no tendency to defleet or turnthe drop wire into an angular relation with the path of travel of thewarp threads, but, on the 'contrary, the warp threads at and the dropwires 8 :as a whole as same the parallel relation as indicated in Fig. 3and avoid chafing of the warp threads against the edges of the dropwire, while the drop wire itself is maintained in proper re lation withthe detector mechanism to cooperate therewith when a drop wire isreleased by its supporting warp thread.

lVhile the invention has been described more particularly with respectto a hair pin type of drop wire, it is to be understood, of course, thatit may be advantageously employed in other types of drop wires, theessential in this respect being that the opening or passageway for thewarp thread shall be off-set to one side of the drop wire to permit thewarp thread to pass through the opening and maintain position at onlyone side of the drop wire.

The invention has been herein shown and described in connection with awarp stop as employed in the'specification and claims is to be construedas the warp stop motion of the loom, warper, or any other machinewherein warp threads are arranged in parallel relation and Wound upon areceiver.

WVhat is claimed is:

1. A drop wire for warp stop motions having a wide and a narrow legportion arranged in parallel relation in the same vertical plane, and awarp opening formed in the wide leg portion and having a laterallyolfset wall at one side of the vertical plane passed through both legportions that a warp thread passed through said opening shall bear uponthe o same side face of each leg portion while said offset wall engagesthe opposite side of the thread.

2. A drop wire for Warp stop motions having a wide leg portion and aseparated narrower leg portion, the side faces of which' are in the samevertical plane, and a warp opening formed in the wide leg portion andhaving a laterally offset wall at one side of the vertical plane passedthrough the corresponding side faces of the two leg portions that bothleg portions shall rest upon the same side of a warp thread passedthrough said opening while said offset wall engages the opposite side ofthe thread.

3. A drop wire for warp stop motions having two separated leg portionsthe side faces of which are in the same vertical plane, and one of saidleg portions being provided with a warp opening having an olfset wall atone side of the vertical plane passing through the corresponding sidefaces of the two leg portions that both leg portions shall bear upon thesame side of a warp thread passed through said opening while the ofisetwall engages the opposite side of the thread.

4. In a warp stop motion, the combination of a transversely movabletoothed detect-or bar, a drop wire having two separated leg portionsforming a detector bar receiving slot, one of said leg portions having awarp opening provided with an offset wall adjacent said slot anddisposed at one side of a vertical plane passed through thecorresponding side faces of the leg portions that the leg portions ateach side of the toothed detector bar shall bear upon the same side of awarp thread passed through said opening while the offset wall engagesthe opposite side of the thread.

In testimony whereof, I have signed my name to this specification.

HARRY A. DAVIS.

